There have conventionally been disclosed and proposed semiconductor devices that have, on an input node side of a current mirror circuit, an external terminal to which to connect an external resistor for setting an internal current in order to permit the internal current to be set freely through appropriate selection of the external resistor by a user (see, for example, Patent Document 1 listed below).
As shown in FIG. 4(a), in some conventional semiconductor devices, an internal resistor RL is inserted between an input node of a current mirror circuit and an external terminal Tex to serve as current limiting means in case the external terminal Tex short-circuits to ground (not necessarily to ground itself but to any comparable low-voltage part; this applies throughout the present specification).
As shown in FIG. 4(b), in some other conventional semiconductor devices, a constant current source is provided that derives a predetermined bias current ibias (i.e., the minimum set level of an internal current i) from an input node of a current mirror circuit to serve as current limiting means not only in case an external terminal Tex short-circuits to ground but also in case the external terminal Tex short-circuits to a supply voltage (not necessarily to a Vcc itself but to any comparable high-voltage part; this applies throughout the present specification) and in case the external terminal Tex is left open.
Patent Document 1: JP-A-H6-180806